The present disclosure generally relates to direct contact steam injection heater diffusers. More specifically, the present invention relates to a steam injection heater diffuser in which steam is diffused into by flowing process fluid through a plurality of holes having a multi-diameter interior to reduce noise.
In diffusers described in previous direct contact steam injection heater patents, such as U.S. Pat. Nos. 6,361,025 and 7,152,851, steam flows through a plurality of straight walled cylindrical orifices or nozzles having sharp edges. The steam is expelled from the diffuser at high velocity into a process fluid flowing past the diffuser perpendicular to the axis of the orifice or nozzle. Under numerous working conditions, these simple nozzles and orifices work sufficiently well in transferring heat energy from the steam to the process fluid while remaining stable and at a decibel level that is comfortable to the human ear. Under certain conditions, however, instability may develop in the jet of exiting steam, which leads to undesirable high frequency, high decibel noise.